Re: getline in /proc

[Simon Vaillancourt]

Yikes, I got that from a sample in a tutorial, I should have RTFM, very sorry 
to have bothered you with that.



Simon









__________________________________________________

>From Stepan Kasal <address@hidden>
Sent Sat 9/17/2005 10:23 AM
To Simon Vaillancourt <address@hidden>
Cc address@hidden
Subject Re: getline in /proc





__________________________________________________

Hello,







On Fri, Sep 16, 2005 at 03:11:37PM -0400, Simon Vaillancourt wrote:



> echo test | gawk 'BEGIN { while (getline < 

> "/proc/anypid/unexistingfile") {print "line="$0}}'







the manpage says:



"The getline command returns 0 on end of file and -1 on an error."







Thus your code contains a bug.  I think this bug occures quite often.







Corrected version:







gawk 'BEGIN { while ( (getline < "/proc/anypid/unexistingfile") > 0 )



        {print "line="$0}}'







And, since it's a good habit to close the files when you are done,



it's customary to use a variable for the file name:







gawk 'BEGIN { a_file = "/proc/anypid/unexistingfile"



        while ( (getline <a_file) > 0 ) {



                print "line="$0



        }



}'







Have a nice day,



        Stepan Kasal